1. Field
Embodiments relate to a compound for an organic photoelectric device and an organic photoelectric device including the same.
2. Description of the Related Art
An organic photoelectric device is a device in which a charge exchange occurs between an electrode and an organic material by using a hole or an electron.
An organic photoelectric device may be classified as follows in accordance with its driving principles. A type of first organic photoelectric device is an electronic device that is driven as follows: excitons are generated in an organic material layer by photons from an external light source; the excitons are separated to electrons and holes; and the electrons and holes are transferred to different electrodes as a current source (voltage source).
A second type of organic photoelectric device is an electronic device driven as follows: a voltage or a current is applied to at least two electrodes to inject holes and/or electrons into an organic material semiconductor positioned at an interface of the electrodes; and then the device is driven by the injected electrons and holes.
For example, the organic photoelectric device may include an organic light emitting diode (OLED), an organic solar cell, an organic photo-conductor drum, an organic transistor, an organic memory device, etc. The organic photoelectric device may include a hole injecting or transporting material, an electron injecting or transporting material, or a light emitting material.
An organic light emitting diode (OLED) has recently drawn attention due to an increase in demand for flat panel displays. In general, organic light emission refers to transformation of electrical energy to photo-energy.
The organic light emitting diode may transform electrical energy into light by applying current to an organic light emitting material. The organic light emitting diode may have a structure in which a functional organic material layer is interposed between an anode and a cathode. The organic material layer may include multi-layers including different materials from each other, e.g., a hole injection layer (HIL), a hole transport layer (HTL), an emission layer, an electron transport layer (ETL), and an electron injection layer (EIL), in order to help improve efficiency and stability of an organic light emitting diode.
In such an organic light emitting diode, when a voltage is applied between an anode and a cathode, holes from the anode and electrons from the cathode may be injected into the organic material layer to generate excitons. The generated excitons may generate light having certain wavelengths while shifting to a ground state.
An organic light emitting diode may include a low molecular aromatic diamine and an aluminum complex as an emission-layer-forming material. The organic material layer may have a structure in which a thin film (hole transport layer (HTL)) of a diamine derivative and a thin film of tris(8-hydroxy-quinolate)aluminum (Alq3) are stacked.
A phosphorescent light emitting material may be used for a light emitting material of an organic light emitting diode in addition to the fluorescent light emitting material. Such a phosphorescent material may emit light by transiting the electrons from a ground state to an exited state, non-radiance transiting of a singlet exciton to a triplet exciton through intersystem crossing, and transiting a triplet exciton to a ground state to emit light.
As described above, in an organic light emitting diode, the organic material layer may include a light emitting material and a charge transport material, e.g., a hole injection material, a hole transport material, an electron transport material, an electron injection material, and the like.
The light emitting material may be classified as blue, green, and red light emitting materials according to emitted colors, and yellow and orange light emitting materials to emit colors approaching natural colors.